Orthotopic Osteogenecity Enhanced by a Porous Gelatin Sponge in a Critical-Sized Rat Calvaria Defect

The gelatin (Gel) powders, derived from acidic and basic extractions of porcine dermis (referred to as AE and BE), were processed for the porous sponge preparation. The disks, which were less than or greater than 500 μm in diameter [small (S) and large (L) pores, respectively] in both extractions and had an interconnected structure respectively, were implanted in critical‐sized defects (CSD) of rat calvaria for 4 and 8 weeks to analyze the bone repair capability. Only the AE‐S disk induced bone formation (over 60%) histomorphometrically in the CSD after 8 weeks, although the collagen orientation of the regenerated bone was still immature. Osteoblastic cell culture until 14 days did not substantiate marked superiority of AE‐S disk regarding the proliferation and the differentiation, although the initial attachment was enhanced on AE‐S disk than BE‐L disk. The results provide the findings that a Gel sponge with a specific porous structure is capable of inducing orthotopic bone formation in vivo environment. Preparation of gelatin disks for bone regeneration: this study is designed to investigate whether a gelatin sponge with a specific porous structure exhibits orthotopic osteogenecity in critical‐sized rat calvarial defects. The results provide the findings that a Gel sponge is capable of inducing new bone formation orthotopically, if the scaffold has a specific porous structure.